A man clicks his nails as he looks at an electronic board displaying share prices outside a brokerage in Tokyo on Thursday. Asian stock markets edged down Monday, Sept. 24, 2012, as confidence in the global economy weakens.

"The reality of weak growth and underlying structural tensions is coming back to haunt markets."

The Fed vowed in mid-September to buy billions in mortgage securities each month until the economy improves in a third round of what is known as quantitative easing, or QE3. The ECB and Bank of Japan followed with their own renewed bond-buying plans.

"There is this struggle between optimism towards QE3 and the concern about the global economic slowdown," said Louis Wong, a director at Phillip Securities in Hong Kong. "So investors are weighing the easing measures of central banks and the health of the global economy."

China's Shanghai Composite Index rose 0.3 percent to 2,032.44, reversing losses earlier in the day. However, the benchmark is still at its lowest point since January 2009.

Chinese stocks are being hurt by a dispute between China and Japan over disputed islands that has heightened tensions between Asia's two biggest economies.

They're also under pressure as investors worry about what Chinese authorities will do to restart growth amid the country's economic slowdown. Wong said it's unlikely that Chinese authorities will unveil any major stimulus measures ahead of the National Day holiday next week or an expected but still unscheduled Communist Party meeting to hand over power to a next generation of leaders.

"This inaction by the Chinese government also weighs," Wong said.

Asian markets were also reacting to some downbeat economic reports released over the weekend. The U.S. Labor Department said that the unemployment rate rose in more than half of states last month, the latest evidence that hiring remains tepid across the world's biggest economy. The World Trade Organization, meanwhile, cut estimates for global trade growth for this year and next. Both reports came out on Friday after Asian markets closed.